Super cool Galileo gravity experiment

Super cool.

Galileo claimed that if there was no air, a cannonball and a feather would, if dropped, hit the ground at the same time. One of the Apollo astronauts did this experiment on the moon with a hammer and a feather.

At the NASA’s Space Power Facility in Ohio, there is a huge chamber which can pump out all the 800K cubic feet of air, some 40 tons, leaving only a few grams. It is a near perfect vacuum. They conduct the experiment and show video in slow motion.

An interesting point is made: We watch this and say that the feather and ball are falling. But wee see this occur in relation to the backdrop. Einstein would say that they not falling.

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  1. Tony Phillips says:

    Galileo never have predicted that in a vaccuum things fall in slow motion. The corollary is: the greater the air pressure, the faster time moves. And Einstein never grasped that.

  2. (X)MCCLXIII says:

    Notwithstanding that I don’t understand general relativity, I find it hard to believe that Einstein, or any sensible man who knew the meaning of the word “fall”, would have said that the feather and the ball were “not falling”.

  3. Kerry says:

    The “Feathers and bowling balls are falling and the earth is thereby heating up from the friction caused by the same!”, and though a sect split off from the Presby-Kelvian warmists, both always express carbon dioxide in terms of weight, pounds or tons “Saved”. (They do, therefore, believe in salvation.) But I believe gases are expressed in terms of volume at pressures, are they not? The cube root of 800k is 92.831, so I am assuming a space 92.831 feet per side, at one atmosphere. And as the percent of carbon dioxide in the atmosphere is .036%, .00036 times 80,000 pounds, (40 tons of air) = 28.8 pounds. The cube root of 28.8 is 3.065. That ‘saved’ carbon dioxide fits into a box about 3 feet cubed. Bear with me, atmospheric theology is a difficult subject, and I am just an amateur. The earth is some 25,000 miles in circumference. Assuming the (breathable atmosphere extends up to 15,000 feet, or about three miles), it is possible to calculate the volume of the atmosphere by subtracting the volume of the earth from the volume of the earth plus atmosphere. Volume= 4/3 ‘pi’ times radius cubed. The earth is 2.60 times 10 to the 11th power, cubic miles. The 15,000 feet increase (in volume) becomes 2.61 times 10 to the 11th power. Giving a volume of the atmosphere .01 times 10 to the 11th power, in cubic miles. How many of those 36″ on a side boxes is that? How many tons of “saved” carbon dioxide can be smashed by a bowling ball?
    Here endeth the rant, and I am returning to simpler meditations. Today’s are the Glorious Mysteries.

  4. Sonshine135 says:

    “Falling” is a relative term. True, if the background wasn’t there, you couldn’t tell the object was falling. You do have an obvious force acting on the objects though- gravity. You’ve simply removed the force that causes resistance.

    An opposite example is when a rocket goes into orbit, it’s forward inertia is at a point where the force of gravity acting on the object cause it to enter into a state of constant “free-fall”. In other words, the Earth’s gravity is always acting on the object, but the object has enough forward inertia to keep it from entering the atmosphere and hitting the Earth.

  5. Kathleen10 says:

    Fascinating, and always inspiring to see our universe and how amazing our God is to create it all and suspend it’s laws at will.
    Is the eye being fooled because of the movement of the earth? Is it that the surrounding walls are moving and that is what creates the blur of the feathers and bowling ball? As Kerry shows, math is God’s language.

  6. The Masked Chicken says:

    Dear Kerry,

    You wrote:

    “Feathers and bowling balls are falling and the earth is thereby heating up from the friction caused by the same!”

    There is no friction in a vacuum and the electrostatic attraction, from whence fluid drag or friction would come, is proportional to the charges divided by the distance of the few molecules of air left to interact with the surface of the ball and the feather. Now, the ball is a sphere, so by Gauss’s Law, the electrostatic potential is zero everywhere, except on the surface, but since there is inter-electron repulsion along the surface, there will never be a localized charge build-up at a point, so no London Forces, thus, to all intents and purposes, the surface area of maximum attraction of the ball to the air is less than 1% of the surface area of the ball parallel to the ground, corresponding to a few microKelvin of energy from drag. The feather, being pointy, bleeds off electrons at the tip, but the migration rate is very small, since a feather is an insulator, so the electron distribution is oblong, but much larger contact area with air molecules in the downward direction than the ball, so greater electrostatic drag (skin friction) is induced, but this is offset by the possible laminar flow induced by the flatness of the feather (not so much for curved feathers). So, overall, a few microKelvins of heating.

    As for CO2 lost or saved, since the vacuum chamber is sealed and the energy of friction is very small, one may calculate the number of CO2 molecules saved fairly accurately. The bond separation energy of the C=O bond in CO2 is 799kJ/mol. Air has an average molecular weight of about 14.5 g/mol, so, assuming 1.45 g of air (to simplify things) in the chamber, this is .1 moles of air, but CO2 only makes up .04% of air, so one has .004 moles of CO2. One needs 2 x .032 kJ = .064 kJ of energy (there are 2 C=O bonds per molecule) to completely break all of the C=O bonds and set them free. Now, how much energy is actually produced by the falling bodies? If the chamber were filled with the usual air mixture of gasses, then, we can use the formula:

    q = m c Δ t

    where, m = 1.45 g = .00145 kg, c = .718 kJ/kg K (using the constant volume heat capacity of air), and Δ t is about .00001 K. Then,

    q = (.00145 kg) (.718 kJ/kg K)(.00001 K) = 1.o4 x 10^-9 kJ of energy,

    But we calculated that it would take .064 kJ to break all of the CO2 and that is if all of the energy went into that process. The nitrogen triple bond energy is only 226 kJ/mol and the O=O bond energy is only 129 kJ/mol, so these would split long before the CO2.

    Exactly how many CO2 molecules would be set free? Well, given the mean free path of air, there would be little heat transfer by kinetic energy beyond a meter, at most, on either side of the objects, but there would be radiative transfer of infrared energy, which we can assume to be negligible. So, assuming a very generous volume of 1 m^3 of heated air around the objects, one can calculate the number of CO2 molecules with that energy by using the Maxwell-Boltzmann distribution, but that involves calculus, which I can’t do in this comment box.

    The Chicken

  7. The Masked Chicken says:

    Oh, by the way, I’ve been a bad Chicken :(

    Mass, today, was concelebrated and, just as the priests were saying the Consecration, I got distracted by the thought that the two priests, at that moment, became, essentially, a single priest – and then it hit me – the concelebrating priests act as a Bose-Einstein condensate! See, near absolute zero, matter behaves in a funky way. There are two types of particles: those having half-integer spin (1/2, 3/2, etc.), such as electrons – these types of particles are called, Fermions, after Enrico Fermi – and particles having zero or integral spin, such as the photon, gravitons, gluons, or the W particle – these are called Bosons, after the Indian physicist, Satyendra Nath Bose. Bose showed that one must use a different type of statistics to describe Bosons than Fermions. Because of their integral spin, the wavefunctions of Bosons can overlap into a single wavefunction at very low temperatures. Thus, at very low temperatures, a collection of bosons condense into a single massive Boson. It was Einstein who figured this out after Bose sent him the statistics, so this condensed state is called a Bose-Einstein condensate. It was predicted in 1924 that helium, which obeys Bose-Einstein statistics, would condense. This was discovered in 1995.

    Of course, then, priests must be Bosons. One can calculate an approximate Boson gas temperature for interacting priests based on how close they are to condensate form. Apparently, Cardinal Burke and Pope Francis must be at high temperatures (yes, things are heating up), because they don’t seem to be condensing together, at all.

    The Chicken

    Fr. Z's Gold Star Award

  8. LarryW2LJ says:

    Apollo 15 – Dave Scott performed the experiment on live TV from the lunar surface. He claimed he was using a Falcon feather – which happened to be the callsign of the LM for that mission – “Falcon”.

  9. The Masked Chicken says:

    Finally, the speeds of the falling objects are sufficiently slow as to be quasi-non-relativistic, so simple Newtonian mechanics will suffice. In either case, one can either describe the objects as falling, the earth as rising, or the whole thing as stationary, depending upon what reference frame one chooses. Choosing the objects to be falling simplifies the math.

    Now, if this were a perfect vacuum, amazingly, heat would still be generated, even though there were no air resistance and, hence, no friction, because of a weird theoretical effect called the Unruh Effect, whereby vacuum pair-pair creations generate heat under acceleration:

    The Chicken

  10. The Masked Chicken says:

    Sorry, the bond energy of O=O is 119 kJ/mol.

    The Chicken

  11. Vincent says:

    Well, it’s the language that underpins the design and building of the Universe. Latin is also His language.

    And of course, cricket is the sport of Heaven!

  12. jflare says:

    It would be interesting to know precisely what Einstein wrote and what the context was. Whether the objects are “falling” only relative to a “background”depends on how both terms are being defined. In this case, we have three objects, two feathers and a bowling ball, of “small” mass. When released from the restraining equipment, these objects definitely move toward the “large”mass of the Earth’s center. This movement would not change even if you painted out the backdrop of the chamber. Therefore, while “falling” may not be entirely accurate, depending on the context, this clip is not entirely honest when it implies that the objects are not moving. They are being accelerated toward the center of Earth, only being stopped by the barrier, which sits on the floor of the vacuum chamber.
    Were this to be done in a vacuum in an environment where the objects could not be accelerated in a negative or positive z direction (“downward” or “upward”), nor a negative or positive y direction (to left or right), but COULD be accelerated in a positive or negative x direction (forward or back), the “small” objects would still be drawn toward the “large” mass in the x direction if the objects were all placed closely enough together.
    I have seen this demonstrated in a college sophomore level physics class.
    Einstein does not contradict Newton to my knowledge. His theories merely explain Newton’s ideas more fully, but the equations reduce to Newton’s laws.

  13. iprimap says:

    As usual, there is some disinformation in this video at the beginning. The talk is given by a young man with no nuclear engineering background. He states that the aluminum in the construction of the walls of the facility were for radiation shielding. Aluminum is a poor gamma shield. The tenth thickness of lead is 2 inches (i.e., it takes 2 inches of lead to reduce incident gamma radiation to 1/10th its value). The tenth thickness of iron is 4 inches. The tenth thickness of aluminum owing to its far less density is even greater. If the walls were constructed for the purpose of shielding, then they would have been made of lead or alternatively steel (which contains much iron). This chamber was originally built to test nuclear-electric power systems (radio-isotope generators) under vacuum conditions. The aluminum provided an vacuum tight barrier against accidental radio-isotope release to the environment, and the concrete surrounding the aluminum provided structural integrity. It was NOT intended to test a fission reactor (like NERVA) brought to criticality (the condition where the number of neutrons leaving a neutron life cycle equal the number entering – there’s an equation but I can’t teach all this stuff here). While this young man’s lecture on gravity is correct, like most popular “scientists,” he doesn’t know fission nuclear engineering.

    PS, here’s NERVA – I had planned to be a part of this, but Nixon killed it and I ended up as a reactor operator on a nuclear submarine instead.

  14. Pigeon says:

    This video makes me fall in love with gravity all over again!

  15. Kerry says:

    Kathleen10, math is certainly not my language. If only our fine host would post something even remotely tangential to the uses of hide glue, aliphatic resin glue and polyvinyl acetates for press-gluing veneers, things I really do know about.
    I was attempting to ridicule the global warming type who express CO2 in pounds, rather than pressure in a container. Too obtuse.
    Great to hear from the Chicken though!

  16. Kerry says:

    Masked Gallus, yes, I know there is no friction in a vacuum, though amongst the many vacuum-headed, great friction develops. Heh.

  17. un-ionized says:

    Kerry, recently I used an app which enables one to find low gasoline prices and it offered to calculate my carbon footprint for a particular trip. Anything for laughs. 400 TONS for a brief vacation trip of 280 miles. I then decided to look up how this thing is “calculated.” Oy. Never mind, I will go anyway thanks. See you at the lake.

  18. Hans says:

    TMC a dit:

    Of course, then, priests must be Bosons.

    Okay, so there are other interesting consequences of this model. Another familiar consequence of B-E statistics is the laser. The existing photons (which are bosons) in the laser cavity cause other photons when generated to be identical to those already there. As the laser continues to operate, the width of the resonance becomes narrower and narrower as the photons become more and more alike.

    So applying this model to priests, establishing bodies of orthodox priests within a diocese would tend to cause those nearby to become more and more orthodox and more and more orthodox priests to be formed, with the effect expanding outward as time progresses, as it is wont to do. (Of course, sadly, the reverse effect is also possible with cores of unorthodox priests.)


    It would seem that deacons, on the other hand, are fermions (following Fermi-Dirac statistics, for anyone who wants to look it up) in the OF at least, probably spin-1/2. While there can be any number of priests concelebrating, there typically would only be one or two deacons assisting, and even then they would be in different states (“Deacon of the Word” and “Deacon of the Eucharist”). That would suggest that priestly ordination, in addition to its other effects, also changes the spin state of the cleric.

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